This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A296665 #13 Dec 22 2017 06:11:39 %S A296665 1,4,20,96,444,2000,8840,38528,166124,710256,3016056,12736064, %T A296665 53530840,224107936,935062544,3890018816,16141765964,66829954736, %U A296665 276135664664,1138932645056,4690042582664,19285299964256,79196366286704,324835930747136,1330905207444344 %N A296665 Row sums of A296666. %F A296665 a(n) = 4^n*((2*(n + 1)*Gamma(n + 1/2))/(sqrt(Pi)*Gamma(n + 1)) - 1). %F A296665 a(n) ~ 4^n*((2*n + 7/4)/sqrt(n*Pi) - 1). %p A296665 a := n -> 4^n*((2*(n + 1)*GAMMA(n + 1/2))/(sqrt(Pi)*GAMMA(n + 1)) - 1); %p A296665 seq(a(n), n=0..24); %Y A296665 Cf. A296666, bisection of A296663. %K A296665 nonn %O A296665 0,2 %A A296665 _Peter Luschny_, Dec 19 2017